The bank was founded by George Knight Budd whose family had a fortune on the East Coast. He was to serve as St. Louis councilman and arranged for the purchase of the land that now forms the municipal building complex including the St. Louis City Hall.

According to company legend, Budd started Boatmen's Savings Institution to help the working class; many of whom worked on riverboats on the Mississippi.

The bank received its state charter on February 16, 1847 and offered 3 percent interest on deposits and invested the first $1,000 in a city bond that paid 6 percent.

Its early history was marked by deadly city-wide disasters in 1849 of a cholera outbreak that killed more than 1,000 and the Great St. Louis Fire of 1849 of May 17-18 that destroyed 23 steamers and at least 430 buildings.

Compounding the bank's problems was the April 5, 1854, robbery in which the bank's secretary Joseph Thornton was implicated because the vault had been opened at night with a bank key. Testifying against him was Joseph Charless, president of the Bank of Missouri, who had received for deposit water and mud-soaked notes from Thornton. Thornton was acquitted but was to shoot and kill Charless on the street afterwards. Thornton was then lynched.

According to company legend, a run on the bank in 1855 was halted when a madame from a bordello deposited $4,500 in gold.

It begame Boatmen's Saving Bank in 1873, Boatmen's Bank in 1890, and Boatmen's National Bank of St. Louis in 1926 when it became a national bank. It remained a local bank until 1969 with the formation of Boatmen's Bancshares and began an acquisition of banks throughout the region including CharterCorp of Kansas City, Missouri and General Bancshares.